Method for handling alarm conditions in a paging system

ABSTRACT

A method for handling alarm conditions from paging stations in a paging system is disclosed. The paging system includes a paging terminal, a plurality of paging stations, and a network manager. When a paging station has an alarm condition, the paging station forwards the alarm to the network manager, which in turn, compares the alarm with an alarm record for that paging station and determines whether or not that alarm is a higher priority than the previous alarms received from the paging station. If so, the network manager transmits a signal to the paging terminal to page the technician responsible for servicing that particular paging station. The technician is paged and dispatched to the paging station for service.

FIELD OF THE INVENTION

The present invention relates to paging systems, and more particularly,to an improved method of handling alarm conditions from pagingtransmitters within the paging system.

BACKGROUND OF THE INVENTION

Paging systems typically include a paging terminal that interfaces withthe public switch telephone network (PSTN) and a plurality of pagingtransmitters that provide signal coverage over a wide geographic region.Examples of such paging systems are described in U.S. Pat. Nos.5,365,569, 5,369,682, and 5,416,808, all to Witsaman et al. and commonlyassigned to the assignee of the present invention and expresslyincorporated by reference herein. These paging systems and others of theprior art are generally configured to allow the simulcasting of a pagingsignal through all of the paging transmitters of the paging system. Byhaving many geographically spaced-apart paging transmitters, a widegeographic region can be reached by the signals of the paging system.The geographic region may be in some cases citywide, statewide, or evennationwide.

As with any large complex system, one or more of the components may failand require repair from time to time by trained technicians. In thepaging system context, the components that fail most often, simply byvirtue of the large number of these components, are the pagingtransmitters. Paging transmitters are also referred to as either pagingstations or base stations.

These paging stations may experience failures that impede the ability ofthe paging stations to operate correctly. These failures lead to what isknown in the art as an alarm condition. Upon such an alarm condition,the paging system must react by dispatching technical personnel to thepaging station to correct the paging station failure that resulted inthe alarm condition.

SUMMARY OF THE INVENTION

The present invention is a method for handling alarm conditions at thepaging stations of a paging system. The paging system includes a pagingterminal, a plurality of paging stations, and a network manager. Inoperation, when a paging station has an alarm condition, the pagingstation contacts the network manager via a dial-up modem over the publicswitch telephone network. The paging station then informs the networkmanager of the particular parameters of the alarm, including the alarmcondition, the time of the alarm condition, and the identification ofthe paging station.

In one aspect of the present invention, the network manager compares thealarm condition with an alarm record for that paging station anddetermines whether or not the received alarm condition is a higherpriority than the previous alarm conditions received from the pagingstation. If so, the network manager forwards a paging alert to thepaging terminal to page a technician responsible for servicing thatparticular paging station. The technician is paged and dispatched to thepaging station for service. In addition, the alarm condition is loggedinto an alarm record for that particular paging station. If the receivedalarm condition is not of higher priority than any of the previous alarmconditions received from the paging station, then the network managerlogs the alarm condition into the alarm record.

In accordance with other aspects of the present invention, when an alarmis received from a paging station, the network manager determineswhether the alarm condition is a new alarm condition or whether it is arepeat of an old alarm condition. If it is a new alarm condition, then atechnician is paged and dispatched to the paging station. In addition,the alarm condition is logged into the alarm record. However, if thealarm is an old alarm condition, a technician is not repaged. The alarmcondition is logged into the alarm record.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing aspects and many of the attendant advantages of thisinvention will become more readily appreciated as the same becomesbetter understood by reference to the following detailed description,when taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a schematic diagram of a paging system configured to operatein accordance with the present invention;

FIG. 2 is a flow diagram illustrating the method of filteringduplicative alarms from a paging station;

FIG. 3 is a flow diagram illustrating the method of prioritizing alarmsfrom a paging station;

FIG. 4 is a schematic diagram of a network manager capable ofimplementing the present invention; and

FIG. 5 is an example of an alarm record.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Turning to FIG. 1, there is shown a paging system 101 in schematicformat. The paging system 101 includes a paging terminal 103, aplurality of paging stations 105, 107, and 109, and a network manager111. Also shown in FIG. 1 is a portable communications device, commonlyknown as a pager 113.

Each of the paging stations 105-109 are communicatively connected to thenetwork manager 111 via one of several alternative methods. In thepreferred embodiment, the paging stations 105-109 are connected viadial-up modems using the public switched telephone network (PSTN).Alternatively, the paging stations 105-109 could be in communicationwith the network manager 111 by means of microwave point-to-pointcommunication systems.

The paging terminal 103 is similarly connected to the paging stations105-109. The communications may be accomplished via the public switchtelephone network, microwave point-to-point communications, or satellitecommunications. The infrastructure upon which the communications betweenthe paging terminal 103 and the paging stations 105-109 are carriedforth are known as the link system.

The network manager 111 can be located at the same locale as the pagingterminal 103. This proximity of location makes communications betweenthe network manager and paging terminal substantially simplified. Asseen in FIG. 1, the network manager is communicatively connected withthe paging terminal 103. In the preferred embodiment, this connection isa direct RS-232 connection.

The network manager 111 serves two primary functions. First, the networkmanager serves to configure the paging system. Those skilled in the artrecognize the types of paging system configuration that are necessary.Insofar as this aspect of the network manager 111 is not particularlygermane to the present invention, this function of the network manager111 will not be discussed further herein. Second, and more germane tothe present invention, the network manager 111 serves to monitor thealarm conditions from the paging stations 105-109. Thus, a majorfunction of the network manager 111 is to receive alarms from pagingstations 105-109 and notify technical personnel of the alarms.

As seen in FIG. 4, the network manager 111 includes a CPU 153, a monitor151, memory 155, input/output device 157, and printer 159. In thepreferred embodiment, the network manager 111 is an IBM-compatiblepersonal computer. As noted above, a principal function of networkmanager 111 is to receive and process alarms from paging stations105-109. Upon receipt of an alarm from a paging station, the networkmanager 111 may provide an audible alarm. In addition, printer 159 mayprovide a printed record of the alarm received from the paging station.The printed records of the alarm will include information such as thedate and time at which the alarm occurred, the paging station's ID,which identifies the particular paging station experiencing the alarm,an alarm identifier and description which describes the alarm beingexperienced, and an alarm serial number.

Turning to FIG. 5, an alarm record 501 having a plurality of alarms 503is shown. The alarm record 501 is stored in memory 155 of the networkmanager 111. An alarm record 501 is stored on each paging station105-109 in the paging system 101. The alarm record 501 is acomprehensive archive of all of the alarm conditions experienced by aparticular paging station. As seen in FIG. 5, each alarm 503 includesthe date 505 and time 507 at which the alarm occurred, the pagingstation's ID 509, an alarm identifier and description 511 whichdescribes the alarm being experienced, an alarm serial number 513, and apage sent indication 515. The page sent indication 515 indicates whethera page to a technician was sent as a result of the alarm. By virtue ofthe present invention further described below, not all alarms willresult in a page being sent to a technician.

In a paging system 101 with tens or even hundreds of paging stationseach reporting multiple alarms, a paging system administrator canquickly see tens or hundreds of alarms in a short period of time. Thisavalanche of alarms quickly overwhelms the administrator. The presentinvention is designed to alleviate such difficulties by filtering thealarms received from various paging stations.

In particular, turning to FIG. 2, at box 201, a paging station transmitsan alarm (referred to as the "current alarm") to the network manager111. The transmission of the current alarm is typically via a dedicateddial-up modem, indicated in FIG. 4 as I/O 157. Next, the network manager111 at box 203 retrieves the alarm record 501 of the paging station frommemory 155. Next, at box 205, all alarms that are duplicates (based uponthe alarm ID and description 511 field) to the current alarm and thatresulted in a page being sent (as determined by the page sent indication515 field) are identified. Oftentimes, the paging station 105 will keepsending duplicate alarms to the network manager 111 if a technician hasnot corrected the alarm condition within a predetermined amount of time.

At box 207, of the previous alarms identified in box 205, adetermination is made as to whether any of these previous alarms arewithin a predetermined filter time from the time of the current alarm.The filter time in the preferred embodiment is four hours, but can beset by the paging system administrator to any length of time. If thereare no previous alarms that are: (1) duplicates to the current alarm,(2) resulted in a page being sent, and (3) within the filter time, thenat box 215, a page is sent to the technician and the ALERT₋₋ ENABLE flag(discussed below) is disabled. Specifically, the technician is alertedby having the network manager 111 page the technician via the pagingterminal 103 of the paging system 101. Next, at box 213, the currentalarm is added to the alarm record and the processing for the currentalarm (now considered a previous alarm for all future alarms) iscomplete.

If, however, at box 207, it is determined that there is a previous alarmthat: (1) is a duplicate to the current alarm, (2) resulted in a pagebeing sent, and (3) within the filter time, then at box 211, anotherdetermination is made. Specifically, at box 211, a determination is madeas to whether a binary flag, ALERT₋₋ ENABLE, has been set to high statusby the technician. The ALERT₋₋ ENABLE flag is used to indicate whetheror not a technician should be alerted when a current duplicate alarm ispresent, regardless of whether or not the current alarm is within thefilter time to a previous alarm resulting in a page. Thus, when theALERT₋₋ ENABLE flag is set to high, the technician will be alerted to acurrent alarm (by page) even if the current alarm is a duplicateresulting in a page within the filter time as determined in box 207.This is executed at box 215. In addition, the ALERT₋₋ ENABLE flag isreset to low after the page is sent to the technician. Next, controlreturns to box 213 and the current alarm is added to the alarm record.

If, however, at box 211, the ALERT₋₋ ENABLE flag is set to low and thecurrent alarm is a duplicate alarm, then the technician will not bealerted. The current alarm will be added to the alarm record at box 213.After box 213, the current alarm will be treated as a "previous alarm"in the alarm record.

To illustrate the above handling of paging alarms in accordance with thepresent invention, the following example is provided. Assume that apaging station sends an alarm to the network manager at 1:00 p.m.signaling a LOW₋₋ OUTPUT₋₋ POWER alarm. Assume further that the filtertime is preset to be 4 hours long and the record is empty. The firstalarm at 1:00 p.m. will result in a page being sent to the technicianbecause the alarm record is empty. There are no previous alarms thatmeet the criteria of boxes 205 and 207. Thus, a page will be sent to thetechnician at box 215, the ALERT₋₋ ENABLE flag is disabled, and thecurrent alarm at 1:00 p.m. will be added to the alarm record at box 213.

Taking the example further, assume that duplicate alarms appear at 2:00p.m., 3:00 p.m., and 4:00 p.m. These alarms will not result in a page ofthe technician. The 2:00 p.m. alarm in proceeding through the process ofFIG. 2 will not result in a page because at boxes 205 and 207, the 1:00p.m. alarm will be identified as being a duplicate alarm that resultedin a page. Further, the 1:00 p.m. alarm is within the filter time offour hours from the 2:00 p.m. alarm. In this example, assume that thetechnician has not enabled the ALERT₋₋ ENABLE flag (discussed belowfurther). Therefore, at box 213, the alarm will simply be added to thealarm record.

Taking the example still further, assume that a LOW₋₋ OUTPUT₋₋ POWERcurrent alarm appears at 5:05 p.m. This current alarm will result in apage to the technician. With reference to FIG. 2, in response to thecurrent alarm, at box 205, the 1:00 p.m. alarm will be identified. Next,at box 207, it will be determined that the 1:00 p.m. alarm is outsidethe four hour filter time from the 5:05 p.m. current alarm. Therefore, apage will be sent to the technician at box 215, the ALERT₋₋ ENABLE flagdisabled, and at box 213, the current alarm will be added to the alarmrecord.

Finally, adding further to this example, assume that at 3:05 p.m., thetechnician enables the ALARM₋₋ ENABLE flag. This can be done using DTMFtone or by dial up modem or personally at the network manager 111.Although the 3:00 p.m. alarm will be treated the same as above, the 4:00p.m. alarm will be treated differently. For example, through box 205 and207, the 1:00 p.m. alarm will be identified as satisfying the criteriaof those boxes. Next, at box 211, the check of the ALERT₋₋ ENABLE flaguncovers that the flag is high. Therefore, a page is sent to thetechnician and the ALERT₋₋ ENABLE flag is reset to low. The currentalarm is then added to the alarm record at box 213.

In accordance with another aspect of the present invention, the"screening" of alarms from paging stations illustrated in FIG. 2 can bemodified to operate on another parameter, namely, the parameter ofpriority.

Turning to FIG. 3, at box 301, a paging station transmits an alarm(referred to as the "current alarm") to the network manager 111. Thetransmission of the current alarm is typically via a dedicated dial-upmodem, indicated in FIG. 4 as I/O 157. Next, the network manager 111 atbox 303 retrieves the alarm record 501 of the paging station from memory155. Next, at box 305, all alarms that are of equal or higher priority(based upon the alarm ID and description 511 field) to the current alarmand that resulted in a page being sent (as determined by the page sentindication 515 field) are identified. Alternatively, in some pagingsystems, each alarm sent by a paging station will further include apriority field that provides a numeric assignment as to the priority ofthe alarm. The priority of the alarm can then be determined from thepriority field of the alarm.

As can be appreciated by those skilled in the art, each paging alarm hasdifferent priority assigned thereto. This priority can then be used toclassify the alarm relative to the other alarms. An example of arelatively low priority alarm would be OUTER₋₋ DOOR₋₋ OPEN, indicatingthat the outer door to the paging station is open. An example of amid-level alarm would be LOW₋₋ OUTPUT₋₋ POWER, indicating that the poweroutput of the paging station is low. An example of a high priority alarmis STATION₋₋ CONTROL₋₋ FAILURE, indicating that the control of thepaging station has failed. This latter case would almost always resultin catastrophic failure of the paging station. In contrast, the firsttwo alarms may or may not result in degraded paging station operation.

At box 307, of the previous alarms identified in box 305, adetermination is made as to whether any of these previous alarms arewithin a predetermined filter time from the time of the current alarm.The filter time in the preferred embodiment is four hours, but can beset by the paging system administrator to any length of time. If thereare no previous alarms that are: (1) equal or higher priority to thecurrent alarm, (2) resulted in a page being sent, and (3) within thefilter time, then at box 315, a page is sent to the technician.Specifically, the technician is alerted by having the network manager111 page the technician via the paging terminal 103 of the paging system101. Next, at box 313, the current alarm is added to the alarm recordand the processing for the current alarm (now considered a previousalarm for all future alarms) is complete.

If, however, at box 307, it is determined that there is a previous alarmthat: (1) is of equal or higher priority to the current alarm, (2)resulted in a page being sent, and (3) within the filter time, then atbox 311, another determination is made. Specifically, at box 311, adetermination is made as to whether a binary flag, ALERT₋₋ ENABLE, hasbeen set to high status by the technician. The ALERT₋₋ ENABLE flag isused to indicate whether or not a technician should be alerted when acurrent alarm is present, regardless of whether or not the current alarmis within the filter time to a previous alarm resulting in a page. Thus,when the ALERT₋₋ ENABLE flag is set to high, the technician will bealerted to a current alarm (by page) even if there is a previous alarmthat is of equal or higher priority resulting in a page within thefilter time to the current alarm, as determined in box 307. This isexecuted at box 315. In addition, the ALERT₋₋ ENABLE flag is reset tolow after the page is sent to the technician. Next, control returns tobox 313 and the current alarm is added to the alarm record.

If, however, at box 311, the ALERT₋₋ ENABLE flag is set to low and thereis a previous alarm that is of equal or higher priority to the currentalarm, then the technician will not be alerted. The current alarm willbe added to the alarm record at box 313. After box 313, the currentalarm will be treated as a "previous alarm" in the alarm record.

To illustrate the above handling of paging alarms in accordance with thepresent invention, this example is provided. Assume that a pagingstation sends an alarm to the network manager at 1:00 p.m. signaling aLOW₋₋ OUTPUT₋₋ POWER alarm. Assume further that the filter time ispreset to be 4 hours long and the alarm record is empty. The first alarmat 1:00 p.m. will result in a page being sent to the technician becausethe alarm record is empty. There are no previous alarms that meet thecriteria of boxes 305 and 307. Thus, a page will be sent to thetechnician at box 315, the ALERT₋₋ ENABLE flag is disabled, and thecurrent alarm at 1:00 p.m. will be added to the alarm record at box 313.

Taking the example further, assume that further alarms appear at 2:00p.m., 3:00 p.m., and 4:00 p.m. that are of lower priority than the 1:00p.m. alarm. These alarms will not result in a page of the technician.The 2:00 p.m. alarm in proceeding through the process of FIG. 3 will notresult in a page because at boxes 305 and 307, the 1:00 p.m. alarm willbe identified as being of equal or higher priority alarm that resultedin a page. Further, the 1:00 p.m. alarm is within the filter time offour hours from the 2:00 p.m. alarm. In this example, assume that thetechnician has not enabled the ALERT₋₋ ENABLE flag (discussed belowfurther). Therefore, at box 313, the current alarm will simply be addedto the alarm record.

Taking the example further, assume that a STATION₋₋ CONTROL₋₋ FAILUREalarm appears at 2:00 p.m. This alarm will result in a page of thetechnician. The 2:00 p.m. alarm in proceeding through the process ofFIG. 2 will result in a page because at boxes 305, the 1:00 p.m. alarmwill not be identified as being of equal or higher priority alarm thatresulted in a page. Thus, at box 307, there are no previous alarms thatare within the filter time. Therefore, at box 315 a page will be sent,the ALERT₋₋ ENABLE flag is disabled, and at box 313, the current alarmwill be added to the alarm record.

Taking the example still further, assume that a OUTER₋₋ DOOR₋₋ OPENcurrent alarm appears at 5:05 p.m. This current alarm will result in apage to the technician. With reference to FIG. 3, in response to thecurrent alarm, at box 205, the 1:00 p.m. alarm will be identified asbeing of equal or higher priority. Next, at box 307, it will bedetermined that the 1:00 p.m. alarm is outside the four hour filter timefrom the 5:05 p.m. current alarm. Therefore, a page will be sent to thetechnician at box 315, the ALERT₋₋ ENABLE flag disabled, and at box 313,the current alarm will be added to the alarm record.

Adding still further to this example, assume that at 3:05 p.m., thetechnician enables the ALARM₋₋ ENABLE flag. This can be done using DTMFtone, by dial up modem or personally at the network manager 111. Assumenext that at 4:00 p.m. a OUTER₋₋ DOOR₋₋ OPEN alarm is received. Throughbox 305 and 07, the 1:00 p.m. alarm will be identified as satisfying thecriteria of those boxes. Next, at box 311, the check of the ALERT₋₋ENABLE flag uncovers that the flag is high. Therefore, a page is sent tothe technician and the ALERT₋₋ ENABLE flag is reset to low. The currentalarm is then added to the alarm record at box 313.

Furthermore, in some paging systems, the paging stations are alsoassigned to a subgroup of paging stations, and thus, each alarm from thepaging station will also include an additional field identifying thesubgroup to which the paging station belongs. In an alternativeembodiment of the present invention, all paging stations of the subgroupwill be considered one paging station. Thus, if an alarm comes from onepaging station in the subgroup, this alarm will have an effect of all ofthe paging stations within the subgroup. Specifically, at boxes 203 and303, the alarm records from all of the paging stations will be retrievedand analyzed. This is yet another method of using the present inventionto filter alarms from a paging system.

While the preferred embodiment of the invention has been illustrated anddescribed, it will be appreciated that various changes can be madetherein without departing from the spirit and scope of the invention.For example, in the preferred embodiment, the screening mechanism in oneexample is duplicate alarms and in the second example priority of thealarms. It can be appreciated that any of the other parameters in alarmscan be used to screen alarms. For example, the alarms can be screened bypaging station ID. Thus, any alarms coming from a particular stationwill not result in a page unless it is outside the filter time or unlessthe technician has enabled the ALERT₋₋ ENABLE flag.

In addition, although the present invention is described as providingfiltering based upon duplication (FIG. 2) and filtering based uponpriority (FIG. 3), these can these filters can be combined whereby thesystem will filter alarms based both on duplicate alarms and priority ofalarms.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. A method of processing acurrent alarm in a paging system said paging system including aplurality of paging stations and a network manager said current alarmoriginating from a one of said paging stations to indicate an alarmcondition at said one of said paging stations, the method including thesteps of:maintaining an alarm record said alarm record including arecord of previous alarms received from each said one of said pagingstations; comparing said current alarm with a predetermined set of saidprevious alarms in said alarm record to determine if said current alarmis a duplicate of any of said predetermined set of said previous alarms;alerting a technician of said current alarm if said current alarm is nota duplicate of any of said predetermined set of said previous alarms;and determining whether an ALERT₋₋ ENABLE flag is high, and if so, evenif said current alarm is a duplicate of any of said predetermined set ofsaid previous alarms, alerting the technician.
 2. The method of claim 1further including the step of determining said set of predeterminedprevious alarms as those previous alarms within a predetermined filtertime of said current alarm.
 3. The method of claim 2 further includingthe step of determining said set of predetermined previous alarms asthose previous alarms within a predetermined filter time of said currentalarm and as those previous alarms that resulted in said technicianbeing alerted.
 4. The method of claim 1 further including the step ofdetermining said set of predetermined previous alarms as those previousalarms that resulted in said technician being alerted.
 5. The method ofclaim 1 wherein the step of alerting includes the step of sending a pageto said technician through said paging system.
 6. The method of claim 1further including the step of adding said current alarm to said alarmrecord.
 7. A method of processing a current alarm in a paging system,said paging system including a plurality of paging stations and anetwork manager, said current alarm originating from a one of saidpaging stations to indicate an alarm condition at said one of saidpaging stations, the method including the steps of:maintaining an alarmrecord, said alarm record including a record of previous alarms receivedfrom each said one of said paging stations; comparing said current alarmwith a predetermined set of said previous alarms in said alarm record todetermine if said current alarm is of higher priority than any of saidpredetermined set of said previous alarms; alerting a technician of saidcurrent alarm only if said current alarm is of higher priority than anyof said predetermined set of said previous alarms; and determiningwhether an ALERT₋₋ ENABLE flag is high, and if so, even if said currentalarm is of lower priority than any of said predetermined set of saidprevious alarms, alerting the technician.
 8. The method of claim 7further including the step of determining said set of predeterminedprevious alarms as those previous alarms within a predetermined filtertime of said current alarm.
 9. The method of claim 8 further includingthe step of determining said set of predetermined previous alarms asthose previous alarms within a predetermined filter time of said currentalarm and as those previous alarms that resulted in said technicianbeing alerted.
 10. The method of claim 7 further including the step ofdetermining said set of predetermined previous alarms as those previousalarms that resulted in said technician being alerted.
 11. The method ofclaim 7 wherein the step of alerting includes the step of sending a pageto said technician through said paging system.
 12. The method of claim 7further including the step of adding said current alarm to said alarmrecord.